Throughout this specification the use of the word “inventor” in singular form may be taken as reference to one (singular) inventor or more than one (plural) inventor of the present invention.
The inventors have identified a number of problems with secure sharing of encrypted information.
Many systems rely on the security of third party services. The inventors have identified that in the case of third party controlled services, including “cloud” storage, remote server storage and other application service providers, the access to the information stored requires the third party to prevent accidental or unwilling disclosure e.g. via mistake, a security breach, legal demand etc and requires control of any related encryption keys by that third party.
Other systems provide user controlled encryption of information and tend to use public/private keys or password generated keys for that encryption. The inventors have identified that these systems have relatively defined sets of users and are also relatively rigid and tend to have difficulty with dynamic and/or efficient management such as scaling, distributed storage, changing group memberships and revocation.
More generally, prior art security systems that deal with encrypted information (including third party and/or user controlled) tend to rely on one or any combination of the following assumptions:                A trusted authority e.g. government, service provider or other third party        Storage system managed keys e.g. encrypted file systems, encrypted databases        Proof of identity e.g. Public Key Infrastructure (PKI)        Password based credentials e.g. file transfer systems        Encryption of information using private keys or password generated keys e.g. document systems        A single user e.g. private secure storage        Message based encryption e.g. email encryption software        Group protocols e.g. multi-cast key management        Transfer based encryption e.g. Secure Sockets Layer (SSL)        Online availability e.g. peer-to-peer services        
It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein.